JP2003109494A - Manufacturing method for electron source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an electron source capable of uniformly activating the whole electron emission element. SOLUTION: An activation process is so formed that set values of a partial pressure of activation gas are changed in multiple stage and a compensation voltage is not applied prevented for a prescribed period of time after changing the set value. Alternatively, the activation processes are repeatedly performed for multiple times while changing a single line wiring or column wiring and the compensation voltage is prevented from being impressed for the prescribed period of time after changing the line wiring or the column wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electron source having an activation step.

[0002]

2. Description of the Related Art Conventionally, two types of electron-emitting devices are known, a hot cathode device and a cold cathode device. Among them, as the cold cathode element, for example, a surface conduction type emission element, a field emission type element (hereinafter referred to as FE type), a metal / insulating layer / metal type emission element (hereinafter referred to as MIM type), etc. are known. ing.

As an example of the FE type, for example, W. P. D
yke & W. W. Dolan, "Field em
"Ission", Advance in Electr
onPhysics, 8, 89 (1956), or
C. A. Spindt, "Physical prop
erties of thin-film field
Emission cathodes with m
lybdenium cones ", J. Appl.
Phys. , 47, 5248 (1976) and the like are known.

As an example of the MIM type, for example,
C. A. Mead, "Operation of tu
nnel-emission Devices ", J.
Appl. Phys. , 32,646 (1961) and the like are known.

The surface conduction electron-emitting device is, for example,
M. I. Elinson, RadioE-ng. Ele
ctron Phys. , 10, 1290, (196
5) and other examples described later are known.

The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs in a small-area thin film formed on a substrate by passing a current in parallel with the film surface. As this surface conduction electron-emitting device, Elinson (Elinso)
n) and the like using the SnO ₂ thin film, as well as the Au thin film [G. Dittmer: "Thin So
lid Films ”, 9, 317 (1972)],
In ₂ O ₃ / SnO ₂ thin film [M. Hartwe
ll and C.I. G. Fonstad: “IEEE
Trans. ED Conf. , 519 (197
5)], and carbon thin films [Hiraki Araki et al .: Vacuum, Vol. 26, No. 1, 22 (1983)] and the like.

As a typical example of the element structure of these surface conduction electron-emitting devices, FIG. Hartwel
Figure 2 shows a plan view of the element according to l etc. In the figure, 300
Reference numeral 1 is a substrate, and 3004 is a conductive thin film made of a metal oxide formed by sputtering.

The conductive thin film 3004 is formed in an H-shaped plane shape as shown in the figure. This conductive thin film 300
The electron emission portion 3005 is formed by performing an energization process called energization forming described later on 4. The interval L in the figure is 0.5 to 1 [mm], and the width W is 0.1 [m.
m] is set. For convenience of illustration, the electron-emitting portion 3005 is shown as a rectangular shape in the center of the conductive thin film 3004, but this is a schematic one and faithfully represents the actual position and shape of the electron-emitting portion. It doesn't mean that.

M. In the above-mentioned surface conduction electron-emitting device including the device by Hartwell, etc., the electron-emitting portion 3005 is obtained by performing an energization process called energization forming on the conductive thin film 3004 before the electron emission.
Was commonly formed.

That is, the energization forming means a constant DC voltage across the conductive thin film 3004, or, for example, 1
A direct current voltage is applied at a very slow rate of about [V / min] to energize the conductive thin film 3004 to locally destroy, deform, or alter the properties thereof, so that electrons are emitted in an electrically high resistance state. That is to form the portion 3005.

Then, a crack is generated in a part of the conductive thin film 3004 which is locally destroyed, deformed or altered. When an appropriate voltage is applied to the conductive thin film 3004 after this energization forming, electrons are emitted near this crack.

The applicant of the present application has proposed an image forming apparatus in which an electron source in which a large number of the above-mentioned electron-emitting devices are arranged and a phosphor which emits visible light by the electrons emitted from the electron sources are combined. (USP506688
3).

Further, when manufacturing the electron source and the image forming apparatus described above, the applicant of the present application adds a new process called energization activation treatment to the electron-emitting device described above, and in this energization activation process, It has been proposed to deposit carbon or a carbon compound in the vicinity of the electron emission portion of the device to increase the emission current from each electron emission device in vacuum.

This energization activation process is a process performed on the electron-emitting device after the energization forming process is completed and is 1 × 1.
By repeatedly applying a predetermined pulse voltage in an environment of a vacuum degree of about 0 ^-2 Pa to about 1 x 10 ^-3 Pa,
This is a process of significantly increasing the emission current from the device.

Here, FIG. 17 shows a schematic diagram of a configuration for measuring the device current If and the emission current Ie flowing through the surface conduction electron-emitting device during the activation process.

This figure shows a measurement system for the device current If and the emission current Ie during the activation process. A conductive thin film 1104 having an electron emitting portion (a thin film 1113 is further formed on the conductive thin film 1104 to form an electron emitting portion) is connected to the activation power source 1 via electrodes 1102 and 1103.
It is connected to 112. Reference numeral 1114 is an anode electrode for supplementing the emission current Ie emitted from the surface conduction electron-emitting device. In this anode electrode 1114,
A DC high voltage power supply 1115 and an ammeter 1116 are connected.

In this activation treatment, under an atmosphere containing an organic substance (hereinafter, this gas atmosphere will be referred to as an activation gas pressure), an appropriate amount is provided between the activation power source 1112 and the element electrode (electron emission portion). It shows that the voltage pulse is repeatedly applied.

Also, the ammeter 1111 and the ammeter 111
6, the device current If and the emission current Ie measured
An example is shown in FIG.

As is apparent from FIG. 18, the activation power supply 1
When the pulse voltage is applied from 112 (FIG. 17),
The device current If and the emission current Ie increase with the passage of time. When the device current If and the emission current Ie reach desired values, the voltage application is stopped and the process ends.

Thus, the reproducibility of the device current If and the emission current Ie is improved by finishing the activation process with the preset device current value and emission current value.

In the following description, the device current If and the emission current Ie whose progress of activation is monitored are referred to as a device current If profile and an emission current Ie profile, respectively.

The inventors of the present application have further researched an electron source in which a large number of surface conduction electron-emitting devices are arranged, and an image display device to which this electron source is applied.

The inventors of the present application have tried, for example, an electron source by the electrical wiring method shown in FIG. That is, it is an electron source in which a large number of surface conduction electron-emitting devices are arranged two-dimensionally and these devices are wired in a matrix as shown in the drawing.

In the figure, 4001 schematically shows a surface conduction electron-emitting device, 4002 is a row direction wiring, and 4003 is a column direction wiring. Row wiring 4002
The column wiring 4003 and the column wiring 4003 actually have a finite electric resistance, but in the figure, the wiring resistance 400
4,4005. The wiring method as described above is called simple matrix wiring.

Although a 6 × 6 matrix is shown for convenience of illustration, the scale of the matrix is not limited to this. For example, in the case of an electron source for an image display device, a desired image display is performed. It arranges and wires the elements enough to carry out.

In the electron source in which the surface conduction electron-emitting devices are wired in a simple matrix, in order to output desired electrons,
Appropriate electric signals are applied to the row wiring 4002 and the column wiring 4003.

For example, in order to drive the surface conduction electron-emitting device of any one row in the matrix, the selection voltage Vs is applied to the row-direction wiring 4002 of the row to be selected, and the rows of the non-selected rows at the same time. The non-selection voltage Vns is applied to the direction wiring 4002. In synchronization with this, a drive voltage Ve for outputting electrons is applied to the column-direction wiring 4003.

According to this method, if the voltage drop due to the wiring resistance 4004 and the wiring resistance 4005 is ignored, a voltage of Ve-Vs is applied to the surface conduction electron-emitting device of the selected row and that of the non-selected row. Ve for the surface conduction electron-emitting device
A voltage of −Vns is applied.

Therefore, by setting Ve, Vs, and Vns to appropriate voltages, it is possible to output electrons of desired intensity only from the surface conduction electron-emitting devices of the selected row, and to each of the column-direction wirings. By applying different drive voltages Ve, it is possible to output electrons with different intensities from the elements of the selected row.

Further, since the response speed of the surface conduction electron-emitting device is high, the length of time for outputting electrons can be changed by changing the length of time for applying the drive voltage Ve.

Therefore, various uses are considered for the electron source in which the surface conduction electron-emitting devices are wired in a simple matrix. For example, by appropriately applying a voltage signal according to image information, the electron source can be used as an electron source for an image display device. Expected to be applicable.

The driving in the case where the voltage drop due to the wiring resistance can be ignored has been described above. However, when a large-scale matrix panel or the like is used, the wiring resistance cannot be ignored, which has an influence on the energization activation process. Therefore, as a result of intensive studies, we have shown that a voltage compensation method for compensating the influence of the voltage drop due to the row-directional wiring by applying a voltage from the column-directional wiring is effective (Patent No. 30).
87849).

[0033]

However, in the case of the above-mentioned prior art, the following problems have occurred.

Examples of the electron source substrate composed of a large number of electron emitting elements include an electron source substrate having a simple matrix configuration in which the electron emitting elements are arranged in a matrix form in M rows and N columns. When the energization activation step as described above is performed on such a substrate, a voltage is applied to a common wiring of M rows and N columns connected to the device electrodes.

However, when the energization activation process is performed on the electron source substrate having the simple matrix structure as described above, there is a problem in that electron emission characteristics vary. The causes include changes in the activated gas atmosphere and effects of wiring resistance due to matrix wiring.
We have diligently studied a method for removing these causes.

As a result, in order to eliminate the influence of the fluctuation of the activation gas atmosphere, the method of removing the influence of the activation gas atmosphere by dividing the energization activation step into a plurality of steps of at least two stages (details will be given). It has been found that (see below) is effective.

Further, it has been found that an energization method (details will be described later) for compensating for the influence of the voltage drop is effective for eliminating the influence of the wiring resistance due to the matrix wiring.

However, when the above-mentioned method for removing the influence of the fluctuation of the activated gas atmosphere and the above-mentioned method for removing the influence of the wiring resistance due to the matrix wiring are used at the same time, the electron emission characteristics are rather varied. As a result, there is an inadequate method for eliminating the variation in electron emission characteristics.

This point is what the present invention is trying to solve.

Hereinafter, the above-mentioned “method of removing the influence of wiring resistance by matrix wiring” and “method of eliminating the influence of fluctuations in the activating gas atmosphere” will be described first, and then these methods, which are the subject of the present invention, will be described. Insufficient points when combined are explained.

The "method of removing the influence of wiring resistance by matrix wiring" will be described.

Prior to explaining the method of removing the influence of the wiring resistance by the matrix wiring, a method of energizing and energizing an electron source having a simple matrix structure will be described.

Here, a method of energizing activation for each row wiring will be described with reference to FIG.

In the figure, 74 is a schematic representation of a surface conduction electron-emitting device, 72 is a row wiring, and 73 is a column wiring. The row wiring 72 and the column wiring 73 have a finite electric resistance 78. This wiring method
Called simple matrix wiring.

This drawing shows the case where a voltage is applied to the wiring (DX2) in the second row. In order to apply the voltage to the second row, all the wiring in the column direction is installed in GND, and the voltage is supplied from the power supply 79 in the second row. Also, ammeter 76
Then, the element current value flowing in the row wiring DX2 is measured.

The voltage waveform used for energization is shown in FIG. The energization activation is performed using a pulse waveform. Here, the case where a rectangular pulse is used as a pulse waveform is shown, and it is shown that the pulse waveform is a rectangular pulse having a pulse width T0 and a pulse period T1.

The electron source having the simple matrix structure is operated by energizing the row wiring units as described above.

However, when such energization activation is performed on an electron source connected to a large-scale matrix wiring, there is a problem that the electron emission characteristic varies depending on the element position. This is because the voltage applied to the element at the end of the matrix is different from the voltage applied to the element at the center of the matrix due to the influence of the voltage drop due to the wiring resistance.

FIG. 22 schematically shows the voltage drop in the matrix wiring.

In FIG. 22, in the element configuration of the simple matrix wiring of m rows × n columns shown in FIG. 20, when the current activation is performed on the elements in the second row, the voltage applied to each element is changed. Shows.

The element in the second row and the first column is F (2,1), the element in the second row and the second column is F (2,2), and the element in the second row and the third column is F (2,3). And the horizontal axis in FIG. 22 is the column number (pixel number)
Is shown. In this figure, the effect of the voltage drop is greatest in the k-th column, and Vfk (<Vf0) is applied to the element F (2, k).
Only applied. Here, Vf0 is the voltage when there is no voltage drop due to the wiring resistance.

In order to remove the influence of such a voltage drop due to the wiring resistance, a voltage is applied from the column side (pixel side) electrode. FIG. 23 shows a circuit for compensating the effect of voltage drop from the column side, and FIG. 24 shows the voltage applied from the column side.

The element current flowing at the time of energization activation is measured by an ammeter 76 (FIG. 20) connected to the row wiring, and the amount of voltage drop due to the row wiring resistance is sequentially calculated from the current value If0. The amount of voltage drop to be output from can be calculated as follows.

For example, the case of activating the elements in the second row will be described.

The voltage Vf0 is applied from the second row, and the voltage drop amount Vfk (k = 1 ... n) from the column wiring side due to the row wiring resistance.
Is applied, Vf0 is applied to all the elements in the second row. Further, since the same voltage is applied to all the elements in the second row, the element current if0 can be considered to be constant if0 = If0 / n.

If the current value measured by the ammeter 76 is If0,
The row wiring element resistance 78 of the matrix portion is set to r0 (here, the column wiring element resistance is sufficiently small and can be ignored).

Then, the voltage to be output from the column wiring is k
For 1 to n / 2, Vfk = 0.5 × k × r0 × If0−0.5 × (k−
1) × k × r0 × if0, and when k is n / 2 + 1 to n, Vfk = 0.5 × (n−k + 1) × r0 × If0-0.
It is calculated as 5 × (n−k + 1) × (n−k) × r0 × if0.

It is understood that the voltage to be output to the column wiring from the current If0 measured from the row wiring can be uniquely determined.

Next, the "method for removing the influence of fluctuations in the activated gas atmosphere" will be described.

Prior to explaining the method for removing the influence of fluctuations in the activation gas atmosphere, the fluctuations in the activation gas atmosphere and the influences of the fluctuations when energization activation is performed on an electron source having a large number of elements will be described. .

When a large number of electron-emitting devices in the electron source substrate are continuously energized in row wiring units, a large amount of the activation gas in the activation processing vacuum container is consumed and the activation gas pressure is reduced. The atmosphere of the activated gas changes until the introduced amount and the consumed amount of the activated gas reach an equilibrium state.

Therefore, the device current characteristics of the electron-emitting device activated in the initial stage and the electron-emitting device activated in the final stage are different, and the uniformity of the electron source is deteriorated.

FIG. 25 shows the difference between the activation gas fluctuation and the device current characteristic. FIG. 25A shows fluctuations in the activation gas in the activation processing vacuum container during the activation processing. Further, FIG. 25B shows an element current If profile at the time of energization activation.

Here, it is assumed that the second row (FIG. 20) is energized and activated in time A, and the third row (FIG. 20) is energized and activated in time B. During the energization activation of the second row, the element current 401 is saturated at a large value because the activation gas partial pressure is high.
Even if the energization activation of the row is performed, the device current 402 is saturated at a small value.

As described above, when a large number of electron-emitting devices are activated by energization at once, the activation gas atmosphere changes, which affects the electron source characteristics.

As a result of diligent studies, we have made it possible to shorten the energization activation time and to deteriorate the uniformity of the emission current value of the electron source by using a plurality of energization activation steps of at least two steps. I found that you can prevent.

That is, this can be realized by using either or both of the following two steps.

(1) A step of changing the row wiring for conducting the current in two or more stages in accordance with the decrease of the concentration of the organic substance by the current activation step (hereinafter, this step is referred to as the current-time-dispersion activation step) To use.

(2) In the energization activation step, a step of varying the activation gas in two or more steps (hereinafter, this step is referred to as a multi-step partial pressure adjustment activation step) is used.

The above two steps will be described in detail.

(1) Energization time dispersion activation step In this step, the row wiring to be energized is changed according to the fluctuation of the activation gas partial pressure. For example, every time a few energizing pulses are applied, the row wiring to be energized is changed to drive.

By using this method, it is possible to suppress variations in the emission current characteristics due to the activation gas partial pressure varying depending on the order in which the energization activation step is performed.

For the sake of brief description, it is assumed that the simple matrix wiring has 2 rows × n columns, and the case where the second row and the first row are energized alternately will be described as an example.

FIG. 26 shows a schematic diagram of the profile of the device current in the second row with respect to the elapsed time and a schematic diagram of the profile of the activated gas partial pressure with respect to the elapsed time.

(STEP1) First, energization activation of the second row is performed up to T1 (au).

(STEP2) At the time when T1 is reached, the energization process for the first row is performed, and the energization for the second row is interrupted.

(STEP1 second time) T2 (au)
Then, since the second row is energized again, the energization to the first row is interrupted.

After that, STEP 1 and STEP 2 are repeated.

The element current ideally behaves like 81 when the element which is left without being energized in the activated gas atmosphere is energized again. That is, the current value at the moment of energization becomes larger than the final value at the time of previous energization (previous STEP 1), sharply decreases, and then the element current stably rises.

(2) Multi-step partial pressure adjustment activation step In this step, the energization activation step is performed by positively controlling the activation gas partial pressure.

In the early stage of activation when the consumption of the activation gas is large, the factor of fluctuation of the activation gas partial pressure can be reduced by increasing the activation gas partial pressure.

By using this method, it is possible to suppress variations in emission current characteristics due to fluctuations in the activation gas partial pressure depending on the order in which the energization activation step is performed.

In order to explain the concept of this step, a method of changing the activation gas partial pressure in two steps will be described by taking as an example the case where the second row of the simple matrix wiring is energized and activated.

FIG. 27 shows a schematic diagram of the profile of the device current in the second row with respect to the elapsed time and a schematic diagram of the profile of the activated gas partial pressure with respect to the elapsed time.

(STEP 1) First, the activation gas partial pressure is set to P
1 is set and the first-stage energization activation is performed until T1 (au).

(STEP2) At time T1, the activation gas partial pressure is set to P2, so that the first-stage energization is interrupted.

(STEP1 second time) When the activation gas partial pressure reaches T2 (au), the second row is energized again.

Ideally, the element current behaves like 81 when the element left in the activated gas atmosphere without being energized is energized again. That is, the current value at the moment of energization becomes larger than the final value at the time of previous energization (previous STEP1), and then sharply decreases (Step1 (2) -1), and then the device current of the element current is stabilized. Elevation occurs (Step 1 (2) -2).

Next, the insufficient points that occur when the “method of removing the influence of the wiring resistance by the matrix wiring” and the “method of eliminating the influence of the fluctuation of the activation gas atmosphere” are used at the same time will be described.

When the "wiring resistance influence removal method by matrix wiring" is used together with the "current-flow time dispersion activation step" and the "multi-step voltage division adjustment activation step", an overvoltage is applied to the element and the element current characteristic In addition, the emission current characteristics may deteriorate.

First, the case where the energization time dispersion activation step is used together will be described.

For the sake of brief description, the matrix wiring is 2 rows × n.
Assuming that it is a column, the case where the second row and the first row are energized alternately will be described as an example.

FIG. 28 shows a profile schematic diagram of the device current in the second row with respect to the elapsed time and a schematic diagram profile of the activated gas partial pressure with respect to the elapsed time.

(STEP1) First, the energization activation of the second row is performed until T1 (au).

(STEP2) At time T1, the energization process for the first row is performed, and the energization for the second row is interrupted.

(STEP3) When T2 (au) is reached, the second row is energized again, and the energization to the first row is interrupted.

As described above, the element current ideally exhibits a behavior like 81 when the element left in the activated gas atmosphere without being energized is energized again. That is, the current value at the moment of energization becomes larger than the final value at the time of previous energization, sharply decreases, and then the element current stably rises.

However, if voltage drop compensation is performed at the time of abrupt current change in the initial stage of STEP 3, an overvoltage will be applied to the element. As a result, the emission current characteristic of the element is deteriorated or the element is broken, which may affect the uniformity of the element characteristic.

This point will be described with reference to FIG. This figure is an enlarged view of (Step 2) in FIG.

Here, the voltage value for compensating for the voltage drop due to the wiring resistance is updated every Δta. As described above, the amount of voltage drop due to the row wiring is calculated based on the current value flowing into the row wiring. Therefore, after measuring the current, the compensation voltage is calculated, and the voltage value is set to the output power supply and output. It takes some time to get there. In this example, it takes Δta from current measurement to voltage output.

The voltage applied from the column wiring is calculated based on the current value Iact2 measured at T2 as follows.

(1) When k is 1 to n / 2, Vfk (T2) = 0.5 × k × r0 × Iact1-0.
It is calculated as 5 × (k−1) × k × r0 × Iact1.

(2) When k is n / 2 + 1 to n, Vfk (T2) = 0.5 × (n−k + 1) × r0 × Ia
ct1-0.5 × (n−k + 1) × (n−k) × r0 ×
Calculated as Iact1.

A voltage corresponding to that value is supplied from the column wiring to T2.
An attempt is made to output in 1 (= T2 + Δta) time, but the device current at that time is Iact2 (<Iact1), and the voltage to be actually output from the column wiring is as follows.

(1) When k is 1 to n / 2, Vfk (T3) = 0.5 × k × r0 × Iact2-0.
5 × (k−1) × k × r0 × Iact2 <Vfk (T
2)

(2) When k is n / 2 + 1 to n, Vfk (T3) = 0.5 × (n−k + 1) × r0 × Ia
ct2-0.5 × (n−k + 1) × (n−k) × r0 ×
Iact2 <Vfk (T2).

Therefore, an overvoltage may be applied to the element, and the element current (emission current) may be deteriorated. This deteriorates the emission current characteristics of the device or destroys the device, which is a cause of adversely affecting the uniformity of device characteristics.

A device current profile in that case is shown at 82.

Next, the case where the multistage partial pressure adjusting activation step is used together will be described.

For the sake of brief description, the case where the second row of the simple matrix wiring is energized and activated will be described as an example.

FIG. 30 shows a schematic diagram of the profile of the device current in the second row with respect to the elapsed time and a schematic diagram of the profile of the activated gas partial pressure with respect to the elapsed time. In addition, FIG.
FIG. 31 is an enlarged view of Step 3 in FIG. 30.

(STEP1) First, the activation gas partial pressure is set to P
1 is set and the first-stage energization activation is performed until T1 (au).

(STEP2) At the time of reaching T1, the activation gas partial pressure is set to P2, so that the first-stage energization is interrupted.

(STEP3) The activation gas partial pressure is T2.
When it becomes (au), the second row is energized again.

As described above, the device current ideally behaves like 81 when the device left in the activated gas atmosphere without being energized is energized again. That is, the current value at the moment of energization becomes larger than the final value at the time of previous energization, sharply decreases, and then the element current stably rises.

However, if voltage drop compensation is performed at the time of abrupt current change in the initial stage of STEP 3, an overvoltage will be applied to the element. As a result, the emission current characteristic of the device is deteriorated or the device is broken, and the process of applying an overvoltage that may have affected the uniformity of the device characteristic is Since the same applies to the case of "combining the conversion step", it is omitted here.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to manufacture an electron source capable of uniformly activating the entire electron-emitting device. To provide a method.

[0118]

In order to achieve the above object, in a method of manufacturing an electron source according to the present invention, a plurality of row wirings and column wirings provided on a substrate and connected to these, respectively. A method of manufacturing an electron source comprising a plurality of electron-emitting devices, wherein after forming an electron-emitting portion in the electron-emitting device, by applying a voltage to the electron-emitting device in an atmosphere of activated gas, In the method of manufacturing an electron source, which has an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion, in the activation step,
For each row wiring or column wiring, while uniformly applying a voltage to all electron-emitting devices connected to one wiring,
An operation of applying a compensating voltage for compensating for the voltage drop caused by one wire to each electron-emitting device is performed, and in the process of performing this operation, the electron-emitting device is operated based on the variation of the partial pressure of the activated gas. It is characterized by performing an operation of limiting the applied voltage for a predetermined time.

When the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is controlled.

When the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is set to a value smaller than the voltage for normal compensation.

The compensation voltage is set to 0 when the voltage applied to the electron-emitting device is limited for a predetermined time.

When the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is set to a predetermined value.

When the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is set to a value calculated from the value of the current flowing through the electron-emitting device measured in advance.

The predetermined time is a time including a time during which the device current of the electron-emitting device measured in advance is decreasing.

The predetermined time is a time including a time in which the time differential value of the device current of the electron-emitting device is negative.

In the electron source manufacturing method of the present invention, a plurality of row wirings and column wirings provided on the substrate,
A method of manufacturing an electron source comprising a plurality of electron-emitting devices each connected to these, wherein after forming an electron-emitting portion in the electron-emitting device, a voltage is applied to the electron-emitting device in an atmosphere of activated gas. In the method of manufacturing an electron source, which has an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion by applying a voltage, in the activation step, each row wiring or column wiring is ,
While uniformly applying a voltage to all electron-emitting devices connected to one wiring, a compensating voltage for compensating for a voltage drop caused by one wiring is applied to each electron-emitting device, and In the process of operation, the set value of the partial pressure of the activated gas is switched in multiple stages, and the compensation voltage is not applied for a predetermined time after the set value is switched.

In the electron source manufacturing method of the present invention, a plurality of row wirings and column wirings provided on the substrate,
A method of manufacturing an electron source comprising a plurality of electron-emitting devices each connected to these, wherein after forming an electron-emitting portion in the electron-emitting device, a voltage is applied to the electron-emitting device in an atmosphere of activated gas. In the method of manufacturing an electron source, which has an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion by applying a voltage, in the activation step, each row wiring or column wiring is ,
While uniformly applying a voltage to all electron-emitting devices connected to one wiring, a compensating voltage for compensating for a voltage drop caused by one wiring is applied to each electron-emitting device, and The operation is repeated a plurality of times while switching the one row wiring or the column wiring, and
It is characterized in that the compensation voltage is not applied for a predetermined time after the row wiring or the column wiring of the book is switched.

The compensation voltage is characterized in that the value of the current flowing through one wire is measured and the calculation is performed based on the measurement result.

[0129]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
Unless otherwise specified, the material, the shape, the relative arrangement, and the like are not intended to limit the scope of the present invention thereto.

Prior to describing the details of the characteristic method of the embodiment of the present invention (limiting the voltage / current for a predetermined time in the activation step), the embodiment of the present invention is applied. The outline of the configuration and manufacturing method of the image display device, which is an application of the electron source, will be described.

(Structure and Manufacturing Method of Display Panel) First, the structure and manufacturing method of the display panel of the image display device will be described with reference to specific examples.

FIG. 7 is a perspective view of a display panel of the image display device, in which a part of the panel is cut away to show the internal structure.

In the figure, 1005 is a rear plate, and 1006.
Is a side wall, and 1007 is a face plate, which form an airtight container for maintaining a vacuum inside the display panel.

When assembling the airtight container, it is necessary to seal the joints of the respective members in order to maintain sufficient strength and airtightness. For example, frit glass is applied to the joints and the joints are exposed to air or nitrogen atmosphere. And 400 ~ Celsius
Sealing can be achieved by firing at 500 degrees for 10 minutes or more. A method of evacuating the inside of the airtight container will be described later.

The rear plate 1005 has a substrate 1001.
Are fixed, and N × M surface conduction electron-emitting devices 1002 are formed on the substrate 1001. Here, N and M are positive integers of 2 or more and are appropriately set according to the target number of display pixels. For example, in a display device intended to display a high definition television, N =
It is desirable to set the number of 3000 and M = 1000 or more. In this embodiment, N = 3072, M = 1
It was set to 024.

N × M surface conduction electron-emitting devices are M
Simple wiring is performed by the row-directional wirings 1003 and the N column-directional wirings 1004. A portion constituted by the substrate 1001, the surface conduction electron-emitting device 1002, the row-direction wiring 1003 and the column-direction wiring 1004 is called an electron source substrate. The manufacturing method and structure of the electron source substrate will be described later in detail.

In the present embodiment, the substrate 1001 of the electron source substrate is fixed to the rear plate 1005 of the airtight container. However, when the substrate 1001 of the electron source substrate has sufficient strength, The electron source substrate 1001 itself may be used as the rear plate of the airtight container.

A fluorescent film 1008 is formed on the lower surface of the face plate 1007. Since the present embodiment is a color display device, the fluorescent film 1008 is separately coated with phosphors of three primary colors of red, green and blue used in the field of CRT.

The phosphors of the respective colors are applied in stripes, for example, as shown in FIG. 8A, and black conductors 1010 are provided between the stripes of the phosphors. The purpose of providing the black conductor 1010 is to prevent the display color from deviating even if the electron irradiation position is slightly deviated, and to prevent the reflection of external light to prevent the display contrast from being lowered. The purpose is to prevent the fluorescent film from being charged up by electrons. Although graphite was used as a main component for the black conductor 1010, other materials may be used as long as they are suitable for the above purpose.

FIG. 8 shows how to separately paint the three primary color phosphors.
The arrangement is not limited to the stripe arrangement shown in FIG. 8A, and may be a delta arrangement as shown in FIG. 8B or an arrangement other than that.

In the case of producing a monochrome display panel, a monochromatic phosphor material may be used for the phosphor film 1008, and a black conductive material is not always necessary.

Also, the rear plate 10 of the fluorescent film 1008.
A metal back 1009 known in the field of CRTs is provided on the surface on the 05 side. The purpose of providing the metal back 1009 is to specularly reflect a part of the light emitted from the fluorescent film 1008 to improve the light utilization rate, to protect the fluorescent film 1008 from the collision of negative ions, and to increase the electron acceleration voltage. For example, it acts as an electrode for applying the voltage, or acts as a conductive path for electrons excited in the fluorescent film 1008.

The metal back 1009 has a fluorescent film 1008.
Was formed on the face plate 1007 substrate, the surface of the phosphor film was smoothed, and Al was vacuum-deposited on the phosphor film. The metal back 1009 is not used when a low voltage fluorescent material is used for the fluorescent film 1008.

Although not used in this embodiment,
For the purpose of applying acceleration voltage and improving the conductivity of the fluorescent film,
A transparent electrode made of, for example, ITO may be provided between the face plate 1007 substrate and the fluorescent film 1008.

To evacuate the inside of the airtight container to a vacuum, after the airtight container is assembled, an exhaust pipe (not shown) and a vacuum pump are connected to each other so that the airtight container has a pressure of about 1 × 10 ⁻⁵ [Pa]. Evacuate to vacuum.

Thereafter, the exhaust pipe is sealed, but in order to maintain the degree of vacuum in the airtight container, a getter film (not shown) is formed at a predetermined position in the airtight container immediately before or after the sealing. To do. The getter film is, for example, a film formed by heating a getter material containing Ba as a main component by heating with a heater or high-frequency heating and depositing the getter material. 10 ^-3 or 1 x 10
^-5 [Pa] vacuum is maintained.

The basic structure and manufacturing method of the display panel have been described above.

Next, a method of manufacturing the electron source substrate used for the display panel will be described.

The electron source substrate used in the image display device according to the embodiment of the present invention is a material, shape, or manufacturing method of the surface conduction electron-emitting device as long as it is an electron source in which surface conduction electron-emitting devices are simply wired. There is no limit.

However, the inventors of the present application found that among the surface conduction electron-emitting devices, the one in which the electron-emitting portion or its peripheral portion is formed of a fine particle film has excellent electron-emitting characteristics,
Moreover, they have found that manufacturing can be easily performed. Therefore, it can be said that it is most suitable for use in an electron source substrate of a high-luminance, large-screen image display device.

Therefore, in the above display panel, a surface conduction electron-emitting device in which the electron-emitting portion or its peripheral portion is formed of a fine particle film is used. Therefore, the basic configuration, manufacturing method, and characteristics of a suitable surface conduction electron-emitting device will be described first, and then the structure of an electron source substrate in which many devices are simply wired will be described.

(Preferable Device Configuration and Manufacturing Method of Surface Conduction Type Electron Emitting Element) Typical configurations of the surface conduction type electron emitting element in which the electron emitting portion or its peripheral portion is formed of a fine particle film include a planar type and a vertical type. There are two types.

(Plane Type Surface Conduction Electron Emitting Element) First, the element structure and manufacturing method of the plane type surface conduction electron emitting element will be described. FIG. 9 is a schematic view of a flat surface conduction electron-emitting device, (a) is a schematic plan view, and (b) is
Is a schematic cross-sectional view.

In the figure, 1101 is a substrate, 1102 and 1103 are element electrodes, 1104 is a conductive thin film, 1105 is an electron emission portion formed by energization forming treatment, and 1113 is energization activation treatment. It is the formed thin film.

As the substrate 1101, for example, various glass substrates such as quartz glass and soda lime glass, various ceramics substrates such as alumina, or an insulating layer made of, for example, SiO ₂ on the above various substrates. A laminated substrate or the like can be used.

Further, the device electrodes 1102 and 1103 provided on the substrate 1101 so as to face each other in parallel with the substrate surface are made of a conductive material. For example, N
i, Cr, Au, Mo, W, Pt, Ti, Cu, Pd,
A material may be appropriately selected from metals such as Ag, alloys of these metals, metal oxides such as In ₂ O ₃ —SnO ₂ and semiconductors such as polysilicon. . To form an electrode, a film forming technique such as vacuum deposition and photolithography,
It can be easily formed by using a combination of patterning techniques such as etching, but it may be formed by using other methods (for example, printing techniques).

The shapes of the device electrodes 1102 and 1103 are properly designed according to the application purpose of the electron-emitting device. Generally, the electrode spacing L is typically several hundred angstroms (1
0 ^{-1 0} m) are designed by selecting an appropriate value from the range of hundreds of micrometers from a range of several tens of micrometers from a few micrometers is preferred for the application in inter alia the display device. Further, the thickness d of the device electrode is usually selected from an appropriate value within the range of several hundred angstroms to several micrometers.

A fine particle film is used for the conductive thin film 1104. The fine particle film described here is a film containing a large number of fine particles as constituent elements (including an island-shaped aggregate).
Refers to. A microscopic examination of the particulate film usually reveals that
A structure in which individual fine particles are arranged apart from each other, a structure in which fine particles are adjacent to each other, or a structure in which fine particles overlap each other are observed.

The particle diameter of the fine particles used for the fine particle film is in the range of several angstroms (10 ^-10 m) to several thousand angstroms, but the preferable range is 10 angstroms to 200 angstroms. Is.

The film thickness of the fine particle film is appropriately set in consideration of various conditions as described below. That is, in order to properly connect the device electrodes 1102 and 1103 with good conditions, to carry out the energization forming described below satisfactorily, and to set the electric resistance of the fine particle film itself to an appropriate value described below. Requirements, etc.

Specifically, it is set within the range of several angstroms to several thousand angstroms, but the range of 10 angstroms to 500 angstroms is particularly preferable.

Materials that can be used to form the fine particle film include, for example, Pd, Pt, Ru, Ag,
Au, Ti, In, Cu, Cr, Fe, Zn, Sn, T
Metals such as a, W, Pb, etc., PdO, S
oxides such as nO ₂ , In ₂ O ₃ , PbO, Sb ₂ O ₃ , etc., HfB ₂ , ZrB ₂ , LaB ₆ , CeB ₆ ,
Borides such as YB ₄ and GdB ₄ , and Ti
Carbides such as C, ZrC, HfC, TaC, SiC, WC, etc., nitrides such as TiN, ZrN, HfN, etc., semiconductors such as Si, Ge, etc., carbon And the like, and is appropriately selected from these.

As described above, the conductive thin film 1104 is formed of a fine particle film. Regarding the sheet resistance value,
It was set to fall within the range of 10 ³ to 10 ⁷ [ohm / sq].

Incidentally, the conductive thin film 1104 and the device electrode 11
02 and 1103 are preferably electrically connected to each other, and thus have a structure in which some of them overlap each other. In the example shown in FIG. 9, the substrate 1101, the device electrodes 1102 and 1103, and the conductive thin film 1104 are stacked in this order from the bottom in the example of FIG. 9, but in some cases, the substrate 1101, the conductive thin film 1104, and the device electrode are stacked from the bottom. 11
It does not matter if the layers are laminated in the order 02, 1103.

Further, the electron emitting portion 1105 is a crack-like portion formed in a part of the conductive thin film 1104, and has an electrically higher resistance property than the surrounding conductive thin film 1104. . The crack is formed by subjecting the conductive thin film 1104 to a later-described energization forming process. Fine particles having a particle diameter of several angstroms to several hundred angstroms may be arranged in the cracks. In addition,
Since it is difficult to accurately and accurately show the actual position and shape of the electron-emitting portion, the electron-emitting portion is schematically shown in FIG.

The thin film 1113 is a thin film made of carbon or a carbon compound, and covers the electron emitting portion 1105 and its vicinity. The thin film 1113 is formed by performing an energization activation process described below after the energization forming process.

More specifically, the thin film 1113 is made of single crystal graphite, polycrystalline graphite, or amorphous carbon, or a mixture thereof, and the film thickness is 500 [angstrom] or less, but 300 [angstrom]. ] The following is more preferable.

Since it is difficult to precisely illustrate the actual position and shape of the thin film 1113, it is schematically shown in FIG. In the plan view (a), the thin film 111
A device in which a part of 3 is removed is shown.

The basic structure of a preferable element has been described above. More specifically, the following element is used in this embodiment.

That is, soda lime glass was used for the substrate 1101, and Ni thin films were used for the device electrodes 1102 and 1103. The thickness d of the device electrodes was 1000 [angstrom], and the electrode interval L was 2 [micrometer].

Pd or P as the main material of the fine particle film
The thickness of the fine particle film was about 100 [angstrom] and the width W was 100 [micrometer] using dO.

Next, a method for manufacturing a suitable flat surface conduction electron-emitting device will be described.

FIG. 10 is a manufacturing process drawing of a surface conduction electron-emitting device. In addition, in each of the process drawings, a schematic cross-sectional view of each element is shown.

(1) First, as shown in FIG.
The device electrode 1102 and the device electrode 11 are provided on the substrate 1101.
Form 03.

In forming these, the substrate 1101 is thoroughly washed in advance with a detergent, pure water, and an organic solvent, and then the material of the element electrode is deposited. However, as a deposition method, for example, a vacuum film forming technique such as a vapor deposition method or a sputtering method may be used.

Thereafter, the deposited electrode material is patterned using photolithography / etching technique,
A pair of device electrodes (1102 and 1103) shown in (a).
To form.

(2) Next, a conductive thin film 1104 is formed as shown in FIG.

In forming this, first, the above-mentioned substrate 1101 is coated with an organic metal solution, dried, and heated and baked to form a fine particle film, and then formed into a predetermined shape by photolithography-etching. Pattern. Here, the organometallic solution is a solution of an organometallic compound whose main element is the material of the fine particles used for the conductive thin film. Specifically, in this embodiment, Pd is used as the main element.
Was used. Further, although the dipping method is used as the coating method in the present embodiment, other methods such as a spinner method and a spray method may be used.

Further, as a method for forming a conductive thin film formed of a fine particle film, other than the method of applying the organic metal solution used in the present embodiment, for example, a vacuum vapor deposition method, a sputtering method, or a chemical vapor phase method. A deposition method may be used in some cases.

(3) Next, as shown in FIG. 13C, an appropriate voltage is applied from the forming power supply 1110 between the element electrode 1102 and the element electrode 1103 to carry out the energization forming process, and the electron is formed. The emitting portion 1105 is formed.

The energization forming treatment means that the electroconductive thin film 1104 made of a fine particle film is energized so that a part of the electroconductive thin film 1104 is appropriately destroyed, deformed, or altered to have a structure suitable for electron emission. It is a process that causes it.

An appropriate crack is formed in the thin film in the portion of the conductive thin film made of the fine particle film that has changed to a structure suitable for emitting electrons (that is, the electron emitting portion 1105). Note that the electric resistance measured between the element electrodes 1102 and 1103 after the formation is significantly increased as compared with the state before the electron emission portion 1105 is formed.

In order to explain the energization method in more detail, FIG. 11 shows an example of an appropriate voltage waveform applied from the forming power supply 1110. When forming a conductive thin film made of a fine particle film, a pulsed voltage is preferable, and in the case of the present embodiment, a triangular wave pulse having a pulse width T1 is continuously provided at a pulse interval T2 as shown in FIG. Applied. In that case, the peak value Vpf of the triangular pulse is
The pressure was sequentially increased. Further, monitor pulses Pm for monitoring the formation state of the electron emission portion 1105 were inserted between the triangular wave pulses at appropriate intervals, and the current flowing at that time was measured by the ammeter 1111.

In the present embodiment, for example, 1.3
In a vacuum atmosphere of about 10 ⁻³ [Pa], for example, the pulse width T 1 is 1 [millisecond] and the pulse interval T 2 is 10.
[Millisecond], and the peak value Vpf is set to 0.1 for each pulse.
The voltage was increased by [V].

Then, the monitor pulse Pm was inserted once every five pulses of the triangular wave were applied. The monitor pulse voltage Vpm was set to 0.1 [V] so as not to adversely affect the forming process. Then, when the electric resistance between the element electrodes 1102 and 1103 reaches 1 × 10 ⁻⁶ [ohm], that is, when the monitor pulse is applied, the current measured by the ammeter 1111 is 1 × 10 ^−7. [A] When the temperature became the following, the energization related to the forming process was terminated.

The above method is a preferable method for the surface conduction electron-emitting device according to this embodiment.
For example, when the design of the surface conduction electron-emitting device such as the material and film thickness of the fine particle film or the device electrode spacing L is changed, it is desirable to appropriately change the energization conditions accordingly.

(4) Next, as shown in FIG.
Appropriate voltage is applied from the activation power supply 1112 between the device electrodes 1102 and 1103 to perform energization activation process to improve electron emission characteristics.

Details of the “energization time dispersion activation step”, “multi-stage partial pressure adjustment activation step”, and “compensation voltage activation step” during the energization activation processing of the electron source, which are the features of the embodiment of the present invention Will be explained later. Here, an outline of the energization activation process will be described.

The energization activation treatment is, concretely, by applying a voltage pulse periodically in an activation gas atmosphere to deposit carbon or carbon compounds originating from an organic compound to obtain electron emission characteristics. Is a process for improving.

Suitable organic substances used herein include alkanes, alkenes, alkyne aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes,
Examples thereof include ketones, amines, organic acids such as phenol, carvone, and sulfonic acid. In particular,
Saturated hydrocarbon represented by CnH2n + 2 such as methane, ethane and propane, CnH2n such as ethylene and propylene
Unsaturated hydrocarbons represented by the composition formulas such as benzene, toluene, benzonitrile, methanol, ethanol, formaldehyde, acetaldehyde, acetone, methyl ethyl ketone, methyl amine, ethyl amine, phenol, formic acid, acetic acid, propionic acid and the like can be used.

In order to explain the energization method in more detail, FIG. 12A shows an example of an appropriate voltage waveform applied from the activation power supply 1112. In the present embodiment, the energization activation process is performed by periodically applying a rectangular wave having a constant voltage. Specifically, a rectangular wave having a voltage Vact of 14 [V], a pulse width T3 of 1 [millisecond], and a pulse interval T4 of 10 [millisecond] was used.

The above energization conditions are preferable conditions for the surface-conduction type electron-emitting device according to the present embodiment, and when the design of the surface-conduction type electron-emitting device is changed, the conditions may be changed accordingly. It is desirable to change.

Reference numeral 1114 shown in FIG. 10 (d) is an anode electrode for capturing the emission current Ie emitted from the surface conduction electron-emitting device, to which the DC high voltage power supply 1115 and the ammeter 1116 are connected. . The substrate 11
When 01 is incorporated into the display panel and then activated, the fluorescent surface of the display panel is set to the anode electrode 11
Used as 14.

While the voltage is being applied from the activation power supply 1112, the emission current Ie is measured by the ammeter 1116 to monitor the progress of the energization activation process, and the activation power supply 1112 is monitored.
Control the behavior of. An example of the emission current Ie measured by the ammeter 1116 is shown in FIG.
When the pulse voltage starts to be applied from 12, the device current If and the emission current Ie increase with the passage of time. When the emission current Ie reaches the preset current value in advance, the voltage application from the activation power supply 1112 is stopped, and the energization activation process ends.

As described above, the flat surface conduction electron-emitting device shown in FIG. 10E was manufactured.

(Characteristics of Surface Conduction Electron-Emitting Element Used in Display Device) The element configuration and manufacturing method of the planar surface conduction electron-emitting element have been described above. Next, the characteristics of the element used in the display device will be described. Describe.

FIG. 13 shows typical examples of (emission current Ie) vs. (device applied voltage Vf) characteristics and (device current If) vs. (device applied voltage Vf) characteristics of the device used in the display device. . The emission current Ie is significantly smaller than the device current If, and it is difficult to show the emission current Ie on the same scale.
Since these characteristics are changed by changing the design parameters such as the size and shape of the element, the two graphs are shown in arbitrary units.

The element used for the display device has the following three characteristics regarding the emission current Ie.

First, a certain voltage (this is the threshold voltage Vth
The emission current Ie sharply increases when a voltage of the above magnitude is applied to the element, while the emission current Ie is hardly detected at a voltage lower than the threshold voltage Vth.

That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie.

Secondly, since the emission current Ie changes depending on the voltage Vf applied to the element, the emission current Ie at the voltage Vf.
The size of e can be controlled.

Thirdly, since the response speed of the current Ie emitted from the element is fast with respect to the voltage Vf applied to the element, the charge amount of electrons emitted from the element depends on the length of time for which the voltage Vf is applied. You can control.

Due to the above-mentioned characteristics, the surface conduction electron-emitting device could be preferably used in a display device.

For example, in a display device in which a large number of elements are provided corresponding to the pixels of the display screen, by utilizing the first characteristic, it is possible to sequentially scan and display the display screen. That is, a voltage equal to or higher than the threshold voltage Vth is appropriately applied to the element being driven, and a voltage lower than the threshold voltage Vth is applied to the element in the non-selected state. By sequentially switching the elements to be driven, it is possible to sequentially scan the display screen for display.

By utilizing the second characteristic or the third characteristic, it is possible to control the light emission brightness, so that it is possible to perform the gradation display.

(Structure of Electron Source Substrate with Simple Wiring of Many Elements) Next, the structure of the electron source substrate with the above surface conduction electron-emitting devices arranged on the substrate and simply wired will be described.

FIG. 14 is a plan view of the electron source substrate used in the display panel shown in FIG.

On the substrate, the surface conduction electron-emitting devices similar to those shown in FIG. 9 described above are arranged, and these devices are simply wired by the row directional wiring 1003 and the column directional wiring 1004. . An insulating layer (not shown) is formed between the electrodes at the intersection of the row wiring 1003 and the column wiring 1004 to maintain electrical insulation.

A cross section taken along the line AA 'in FIG. 14 is shown in FIG.

The electron source having such a structure has a row wiring 1003, a column wiring 1004, and
After forming the inter-electrode insulating layer (not shown), the device electrode of the surface conduction electron-emitting device, and the conductive thin film, the row wiring 1
It was manufactured by supplying power to each element through 003 and the column-direction wiring 1004, and performing an energization forming process and an energization activation process.

<Activation Step of Row (Column) Units of Electron Source Substrate in which Many Elements are Wired in Simple Matrix> Next, a method of activating the above-mentioned electron source substrate in which simple wiring is performed in row (column) units will be described. . By using this method, a large number of elements can be activated at the same time, so that the activation processing time can be shortened.

FIG. 20 shows the case where the device of the second row (Dx2) is activated for the surface conduction electron-emitting device wired like the electron source substrate shown in FIG. The voltage application method is shown.

As shown in FIG. 20, the surface type electron-emitting device 74 is connected to the row wiring 72 and the column wiring 73.
In the figure, reference numeral 77 is an activating power supply, and 76 is an ammeter for measuring the element current, so that a line wiring other than the second row (Dx2) is applied in order to apply a voltage only to all the elements in the second row. 72
And all column wirings 73 are grounded. By connecting the elements in this manner, a voltage is applied to the elements in the row direction, and the activation process can be performed.

The element current measurement for observing the progress of the activation process is performed by the ammeter 76. The activation completion condition was when the sum of the device currents was saturated.

Although the case where the elements in the second row (Dx2) are activated is described here, the elements in other rows can be activated as well by using the same method.

Although the activation process in units of row wiring has been described here, the activation process in units of column wiring can be performed by using the same method.

Furthermore, the method of observing the progress of the activation process is not limited to the device current measurement, and emission current measurement may be used.

Heretofore, the configuration, the manufacturing method, and the operation of the image display device applicable in the present embodiment have been described.

Next, the characteristic contents of the present embodiment will be described (first embodiment). In the embodiment of the present invention, a method is adopted for energizing and energizing a large number of elements in a short time. It is used when the "multi-step partial pressure adjustment activation step" and the "compensation voltage application step" are performed simultaneously. In addition, the present embodiment is characterized in that the compensation voltage at the start of energization is not output for a certain period of time. By using this method, the activation process can be performed more uniformly than in the conventional activation method, and an electron source with uniform emission current characteristics can be obtained.

In this embodiment, a large number of surface conduction electron-emitting devices are arranged in a simple matrix (the number of devices is 1024 × 30).
72) A method of manufacturing an image display device having the electron source substrate, mainly an example of an electron source activation step will be described.

As a method of activating a large number of elements, a row-unit activation step of performing the activation step for each row will be performed.

In the following description, only the energization activation step for the second row will be described, but the same steps are performed for the other rows.

First, FIG. 1 shows the configuration of an activation processing control device used in the electron source manufacturing method according to the embodiment of the present invention.

FIG. 1 is a diagram showing an example of an energization activation device for a surface conduction electron-emitting device according to the present embodiment. The electron source substrates shown in FIG. 7 are connected as shown in FIG. 1 to perform activation processing.

In FIG. 1, reference numeral 101 denotes an electron source substrate of a multi-surface conduction electron-emitting device which is connected for activation by energization, and has m rows × n columns (m = 10 in this embodiment).
A plurality of electron-emitting devices are connected by simple matrix wiring of 24, n = 3072). Further, it is assumed that the forming has already been completed. This electron source substrate is connected to a vacuum exhaust device (not shown), and is 1 × 10 ⁻³ to 1
Evacuated to about ^-2 [Pa].

Reference numeral 102 denotes a row selection circuit for selecting a row to be activated. A row direction wiring is selected in accordance with an instruction from the control circuit (control unit) 104, and the power supply 10 is connected to the selected row direction wiring.
The voltage is applied from 3. The row selection circuit 102 also includes an ammeter 313 (see FIG. 2) to detect the current flowing in the row-direction wiring of the electron source.

The control circuit 104 takes in the current value detected by the current detection portion of the row selection circuit and sets the voltage value necessary for energization activation to the power supplies 103 and 113. Dx1
~ Dxn indicates row-direction wiring terminals of the electron source substrate 101,
Dy1 to Dyn indicate column direction wiring terminals of the electron source substrate 101. The control unit 104 has a timer to adjust the energization activation time and the partial pressure change time.

Next, the operation of the row selection circuit 102 will be described with reference to FIG. FIG. 2 is a circuit diagram showing a circuit configuration of the row selection circuit 102.

The row selection circuit 102 has a switch such as a relay or an analog switch, and has switches SWx1 to SWxm.
Up to m switches are arranged in parallel, and the output of each switch is connected to each of the row wiring terminals Dx1 to Dxm of the electron source substrate 101.

These switches are controlled by the control signal of the control unit 104, and the power supply 103 is connected to the row wiring to be driven.
It operates so that the voltage waveform from is applied. In FIG. 2, the line of the second row (Dx2) is selected, the voltage is applied only to the row wiring terminal Dx2, and the other line (non-selected row wiring) is connected to the ground.

FIG. 23 is a schematic diagram showing voltage application in this embodiment.

The figure shows that only the elements in the second row are connected to the row side driving voltage source and the other rows are connected to the ground.

The column side is connected to the column side driving voltage source.

In the following, regarding the energization activation method in the present embodiment, the voltage dividing control method will be described, and then the voltage application method will be described.

The applied waveform during the activation processing is the voltage peak value V
x is 14V, pulse width Tw is 1 msec, pulse period T
The p was set to 10 msec (FIG. 3 (a)).

FIG. 3B shows the voltage output from the column side. Here, FIG. 3B shows the voltage output from the column side wiring 1900. The voltage value applied from the column side is determined by the calculation method described in the problems to be solved by the invention.

The activation process is terminated at the time when the element current value of one row obtained from the ammeter 313 (see FIG. 2) described above is saturated.

First, the <multi-stage partial pressure adjusting energization activation method> will be described with reference to FIG.

In the present embodiment, the energization activation method is performed in which the activation gas partial pressure is changed in two steps.

In this embodiment, trinitrile is used as the activating gas and the partial pressure of the first step is 1 × 10 ^-2 Pa.
(P1) The partial pressure at the second stage was set to 2 × 10 ⁻⁴ Pa (P2).

The end time of the first stage is set to 2 minutes (T
1) The starting time of the second stage was 3 minutes (T2). The time required for switching from the first stage to the second stage is determined by the exhaust capacity of the vacuum exhaust device and the activation gas introduction method.

Then, the compensation voltage interruption time ΔT is set to 3 minutes.

Next, the voltage applying step will be described.

In this embodiment, a method of applying 14 V from the row wiring and applying a compensation voltage from the column wiring side to compensate for the voltage drop due to the wiring resistance of the row wiring is used.

In this embodiment, the inter-element resistance 7 of the row wiring is
8 (see FIG. 23) r0 is 1 mΩ. The resistance between elements of the column wiring is sufficiently small and can be ignored.

As the compensation voltage output, the current flowing at the time of energization activation is measured once per second by the current detection unit of the row wiring current, the compensation voltage value is calculated based on the current value, and the voltage is output from the column side. I went there.

Since the calculation method is the same as that described in the section of the problem to be solved by the invention, the description thereof will be omitted.

At the second partial pressure, 15 minutes after the start of activation (T
3 = 18 minutes), the device current If profile was saturated, and the current value became approximately 5 A, so the activation was terminated.

For ΔT used this time, the time during which the current change at the initial stage of the second stage was large was estimated in advance by experiments.

The drive sequence will be described with reference to FIGS. 3 and 4.

(Step 1) Since the device current in the second row increases with the start of energization as shown in FIG. 4, the voltage applied from the column side also increases with the start of energization.

(STEP 2) The output voltage from the row side and the column side is cut and the activation gas partial pressure is changed in order to interrupt the activation of the first stage 2 minutes after the start of activation.

(STEP 3-1) After the activation gas partial pressure is set for the second stage activation, voltage application is restarted from the row wiring. However, the compensation voltage is not applied during ΔT.

(STEP 3-2) After the time ΔT has passed,
The compensation voltage application is restarted.

When the device current is sufficiently saturated, driving is ended and the activation process is ended.

The device current profile in this embodiment is as shown by profile 83 in FIG. 4 when the method of this embodiment is used.

This profile 83 is the profile 8
2, the element does not deteriorate rapidly, and a reaching current that is almost the same as the ideal element current profile 81 is obtained.

After the energization activation step of the second row is completed, the energization activation step is performed sequentially for the row wirings other than the second row, thereby performing the energization activation step in which the element characteristics are not deteriorated by the overvoltage. It has become possible.

Therefore, an electron source with good uniformity could be obtained.

In this embodiment, the application of the overvoltage to the element is suppressed by not outputting the initial compensation voltage of the multi-stage for a certain period of time, but the invention is not limited to this.

For example, a method of measuring a device current measured from a row wiring, monitoring a period of abrupt fluctuation, and not applying a compensation voltage is also preferably used.

Further, instead of the compensation voltage, the voltage applied to the entire one row wiring may be limited.

Further, instead of completely stopping the output of the compensation voltage, the compensation voltage of a value smaller than the voltage for the normal compensation may be output. In this case, a compensation voltage having a predetermined value may be output, or a value calculated from a previously measured current value flowing through the electron-emitting device may be used.

Considering that the period in which the element current at the initial stage of the multi-step changes abruptly is the period in which the element current decreases, the compensation voltage is changed while the time differential of the element current is "negative". The method of not outputting is also preferably implemented.

In the present embodiment, the activation end condition is based on the detection of the saturation of the activation current, but the present invention is not limited to this, and the method of measuring from the emission current Ie profile characteristic, the efficiency, η (= Ie / If) Method of measuring from profile characteristics, device current If during activation If
-Applied voltage V characteristics, emission current Ie-Applied voltage V characteristics, efficiency η-Applied voltage V characteristics can also be preferably used.

In the present embodiment, the energization method of applying from both sides of the row wiring is performed, but the present invention is not limited to this, and the energization method of applying from one side is also preferably used.

Further, in the present embodiment, in the <compensation voltage applying step>, the method of correcting the influence of the voltage drop in the row wiring by applying the voltage from the column wiring is adopted, but the present invention is not limited to this. Instead, it is also preferably implemented by using an application method in which rows and columns are interchanged.

In the present embodiment, the method of changing the activation gas partial pressure in two steps is used in the <multi-step partial pressure adjustment energization activation method>, but the present invention is not limited to this, and the element film material, It may be appropriately changed depending on the activated gas material. Therefore, even if it is divided into three or more stages, it is preferably implemented.

In this embodiment, the method of sequentially calculating the compensation voltage output value during the energization activation step has been described.
The present invention is not limited to this, and the voltage to be output may be set in advance based on the element current value measured at the time of activation.

(Second Embodiment) In the second embodiment of the present invention, a method is employed for energizing and energizing a large number of elements in a short time. It is used when the "application step" is performed at the same time. And
The present embodiment is characterized in that the compensation voltage at the start of energization is not output for a certain period of time. With this method,
As compared with the conventional activation method, the activation treatment can be performed uniformly, and an electron source with uniform emission current characteristics can be obtained.

For the sake of simplicity of explanation, portions different from the first embodiment will be mainly described below.

The configuration of the activation processing control device according to the present embodiment is the same as that of the first embodiment described above, and will be omitted.

In this embodiment, as a method for activating a large number of elements, a row-unit activation step of performing the activation step for each row is performed. Further, in the present embodiment, from the first line to 1
The “time-dispersed energization activation method” is used for the element in the 024th row and the 1024th row.

In the following, regarding the energization activation method in the present embodiment, the voltage division control method will be described, and then the voltage application method will be described.

First, the partial pressure control will be described with reference to FIG.

Using trinitrile as the activating gas,
The set partial pressure value P0 was set to 5 × 10 ⁻³ Pa. The switching of the row wirings to be activated by energization was performed at intervals of 5 minutes (Tcycle). Then, one minute immediately after switching the row wiring (= ΔT2)
In the case, the compensation voltage is not applied from the column side. For ΔT2 used this time, the time during which the current change at the initial stage of the multistage was large was estimated in advance by experiments.

Next, the voltage applying step will be described.

In this embodiment, a method of applying 14 V from the row wiring and compensating for the voltage drop due to the wiring resistance from the column wiring side is used. In the present embodiment, the inter-element resistance 78 of the row wiring (see FIG. 23) r0 is 1 mΩ. The resistance between elements of the column wiring is sufficiently small and can be ignored.

The compensation voltage output is obtained by measuring the current flowing at the time of energization activation by the row wiring current detecting section once a second, calculating the compensation voltage value based on the current value, and outputting the voltage from the column side. went.

The method of calculating the compensation voltage value is as described in the problems to be solved by the invention described above.

The applied waveform during the activation process has a voltage peak value of 14 V, a pulse width of 1 msec, and a pulse period of 10 ms.
ec was set (FIG. 5A).

FIG. 5B shows the voltage output from the column side wiring number 1900. The voltage value applied from the column side is
It is determined by the calculation method described in the problems to be solved by the invention.

The activation process is terminated when the element current value of one row obtained from the ammeter 313 (see FIG. 2) described above is saturated.

The activation process was started from the first line, and after that, the second line, the third line, ..., The 1024th line were driven, and then the first line was driven.

The drive sequence will be described with reference to FIGS. 5 and 6.

(STEP1) Since the device current in the first row increases with the start of energization as shown in FIG. 6, the voltage applied from the column side increases with the start of energization.

Since the activation of the first stage is completed 5 minutes after the activation is started (= Tcycle), the output voltage from the row side and the column side is cut off, the energization of the first row is terminated, and the second row is activated. Prepare for energizing.

(STEP2) In order to apply a voltage to the second row, the switches of the row selection circuit 102 (see FIG. 1) are connected to SX2 only in the second row, and all but the second row are connected to the ground. When the connection ends, energization starts.

The activation of the first stage is completed 5 minutes after the activation is started (= Tcycle), so that the output voltages from the row side and the column side are cut and the energization of the second row is terminated. Next, preparations are made to energize the third row. Below 102
Power is supplied to the fourth line for 5 minutes (= Tcycle).

(STEP3) In order to apply the voltage to the first row again, the switches of the row selection circuit 102 are set to S only for the first row.
Connect to X1 and connect all but the first row to ground. When the connection ends, energization starts. However, the compensation voltage is not applied from the column side for 1 minute (= ΔT2). Time Δ
When T2 passes, the compensation voltage application is restarted.

Since the second-stage activation is completed 5 minutes after the activation is started, the output voltage from the row and column sides is cut to 1
Stop energizing the row. Next, preparation for energizing the second row is performed.

(STEP4) In order to apply the voltage to the second row, the switch of the row selection circuit 102 is set to SX2 only in the second row.
And connect everything except the second line to ground.
When the connection ends, energization starts. However, 1 minute (=
For ΔT2), the compensation voltage is not applied from the column side. Time ΔT2
After the time, the compensation voltage application is restarted.

Since the second-stage activation is completed 5 minutes after the start of activation, the output voltage from the row and column sides is cut off, and 2
Stop energizing the row. Next, preparations are made to energize the third row.

Thereafter, the same energization is conducted for 5 minutes (= Tcycle) up to the 1024th line.

Preparation for applying a voltage to the first row is started again.

In this embodiment, STEP 3 and STEP 3
Activation is performed by repeating 4 and 1
The saturation of the device current If profile was confirmed after repeating 5 times, so the activation process was terminated.

FIG. 6 shows a device current profile in this embodiment.

Using the method of this embodiment, the device current has a profile 83. In this profile, the element does not suddenly deteriorate as in 82, and a reaching current almost equal to that of the ideal element current profile 81 is obtained.

When the current-carrying activation process was performed on all the devices in the 1024th row, since the overvoltage was not applied during the activation process, the current-carrying activation process without deterioration of the device characteristics became possible. Therefore, an electron source with good uniformity could be obtained.

In this embodiment, the application of the overvoltage to the element is suppressed by not outputting the initial compensation voltage at the multi-stage for a certain period of time, but the invention is not limited to this.

For example, a method of measuring a device current measured from a row wiring, monitoring a period of abrupt fluctuation, and not applying a compensation voltage is also preferably used.

Further, instead of the compensation voltage, the voltage applied to the entire one row wiring may be limited.

Further, instead of completely stopping the output of the compensation voltage, the compensation voltage of a value smaller than the voltage for the normal compensation may be output. In this case, a compensation voltage having a predetermined value may be output, or a value calculated from a previously measured current value flowing through the electron-emitting device may be used.

Considering that the period in which the element current in the initial stage of the multi-step changes abruptly is the period in which the element current decreases, the compensation voltage is maintained while the time differential of the element current is "negative". The method of not outputting is more preferably implemented.

In the present embodiment, the activation end condition is based on detecting the saturation of the activation current, but the present invention is not limited to this, and the method of measuring from the emission current Ie profile characteristic, the efficiency η (= Ie / If) Method of measuring from profile characteristics, device current If during activation If
-Applied voltage V characteristics, emission current Ie-Applied voltage V characteristics, efficiency η-Applied voltage V characteristics can also be preferably used.

In the present embodiment, the energization method of applying from both sides of the row wiring is performed, but the present invention is not limited to this, and the energization method of applying from one side is also preferably used.

Further, in the present embodiment, in the <compensation voltage applying step>, the method of correcting the influence of the voltage drop in the row wiring by applying the voltage from the column wiring is adopted, but the present invention is not limited to this. Instead, it is also preferably implemented by using an application method in which rows and columns are interchanged.

In this embodiment, the method of sequentially calculating the compensation voltage output value during the energization activation step has been described.
The present invention is not limited to this, and the output voltage may be set in advance based on the element current value measured during activation.

[0309]

As described above, by using the electron source manufacturing method of the present invention, the activation process can be uniformly performed on the entire electron-emitting device.

[Brief description of drawings]

FIG. 1 is a schematic view of an energization activation device.

FIG. 2 is a circuit diagram of a row selection circuit provided in the energization activation device shown in FIG.

FIG. 3 is a drive sequence explanatory diagram of the method for manufacturing the electron source according to the first embodiment of the present invention.

FIG. 4 is a drive sequence explanatory diagram of the method for manufacturing the electron source according to the first embodiment of the present invention.

FIG. 5 is a drive sequence explanatory diagram of an electron source manufacturing method according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a drive sequence of a method of manufacturing an electron source according to a second embodiment of the present invention.

FIG. 7 is a partially cutaway perspective view of a display panel of the image display device.

FIG. 8 is a diagram showing an arrangement configuration example of a phosphor and a black conductor.

FIG. 9 is a schematic view of a planar surface conduction electron-emitting device.

FIG. 10 is a manufacturing process diagram of a surface conduction electron-emitting device.

FIG. 11 is a diagram showing an example of a voltage waveform during a forming step.

12A is a diagram showing an example of a voltage waveform during a forming process, and FIG. 12B is a diagram showing an emission current amount during an activation process.

FIG. 13 is a current characteristic diagram of an electron-emitting device.

FIG. 14 is a plan view of an electron source substrate used for a display panel.

15 is a cross-sectional view taken along the line A-A ′ in FIG.

FIG. 16 is a schematic plan view showing a device configuration of a typical surface conduction electron-emitting device.

FIG. 17 is a schematic configuration diagram for measuring a device current and an emission current flowing in a surface conduction electron-emitting device during activation processing.

FIG. 18 is a diagram showing changes in a device current value and an emission current value during an activation process.

FIG. 19 is a plan view of an electron source in which surface conduction electron-emitting devices are wired in a matrix.

FIG. 20 is a device configuration diagram for energizing activation for each row wiring.

FIG. 21 is a voltage waveform diagram used for energization in the activation process.

FIG. 22 is a schematic diagram showing a state of voltage drop in a matrix wiring.

FIG. 23 is a circuit configuration diagram for applying a compensation voltage that compensates for the influence of a voltage drop.

FIG. 24 is an explanatory diagram of a compensation voltage to be applied.

FIG. 25 is a diagram for explaining a change in activated gas and a difference in device current characteristics.

FIG. 26 is a diagram showing how the element current changes and the activation gas partial pressure changes in the case of changing the row wiring for energization according to the variation of the activation gas partial pressure.

FIG. 27 is a diagram showing how the element current changes and the activation gas partial pressure changes when the energization activation step is performed by positively controlling the activation gas partial pressure.

FIG. 28 is a diagram showing changes in element current and changes in activation gas partial pressure when the method of removing the influence of wiring resistance and the energization time dispersion activation step are used in combination.

FIG. 29 is an enlarged view of Step 2 in FIG. 28.

FIG. 30 is a diagram showing how the element current changes and the activation gas partial pressure changes when the method of removing the influence of the wiring resistance and the multi-step partial pressure adjustment activation step are used together.

31 is an enlarged view of Step 3 in FIG. 30. FIG.

[Explanation of symbols]

72 lines wiring 73 column wiring 74 Surface type electron-emitting device 76 ammeter 79 power 101 electron source substrate 102 row selection circuit 103,113 power supply 104 control circuit 313 ammeter 401 element current 402 Element current 1001 substrate 1002 surface conduction electron-emitting device 1003 row direction wiring 1004 Column direction wiring 1005 rear plate 1006 side wall 1007 face plate 1008 fluorescent film 1009 metal back 1010 conductor 1101 substrate 1102, 1103 Element electrodes 1104 Conductive thin film 1105 Electron emission unit 1110 power supply 1111 ammeter 1112 power supply 1113 thin film 1114 Anode electrode 1115 power supply 1116 ammeter 3004 Conductive thin film 3005 Electron emission unit 4002 row direction wiring 4003 Column direction wiring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazusa Kawade             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation (72) Inventor Takahiro Oguchi             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation

Claims (11)

[Claims] 1. A method of manufacturing an electron source, comprising: a plurality of row wirings and column wirings provided on a substrate; and a plurality of electron-emitting devices connected to the respective wirings. Manufacture of an electron source having an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion by applying a voltage to the electron emitting element in an atmosphere of an activated gas after forming the emitting portion. In the method, in the activation step, a voltage is uniformly applied to all the electron-emitting devices connected to one wiring for each row wiring or column wiring,
A compensating voltage for compensating for a voltage drop caused by one wiring is applied to each electron-emitting device, and in the process of performing this operation, the electron-emitting device is operated based on the fluctuation of the partial pressure of the activated gas. A method for manufacturing an electron source, which comprises performing an operation of limiting an applied voltage for a predetermined time. 2. The method of manufacturing an electron source according to claim 1, wherein the voltage applied to the electron-emitting device is limited by a predetermined time by controlling the compensation voltage. 3. The electron source according to claim 1, wherein when the voltage applied to the electron-emitting device is limited for a predetermined period of time, the compensation voltage is set to a value smaller than a voltage that normally compensates. Manufacturing method. 4. The method of manufacturing an electron source according to claim 1, wherein the compensation voltage is set to 0 when the voltage applied to the electron-emitting device is limited for a predetermined time. 5. The method of manufacturing an electron source according to claim 1, wherein when the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is set to a predetermined value. 6. When the voltage applied to the electron-emitting device is limited for a predetermined time, the compensation voltage is set to a value calculated from the value of the current flowing through the electron-emitting device measured in advance. Item 2. A method of manufacturing an electron source according to Item 1. 7. The predetermined time period is a time period including a time period during which the device current of the electron-emitting device is measured in advance, and the predetermined time period is included in the predetermined time period. A method for manufacturing the described electron source. 8. The predetermined time is a time including a time in which a time derivative of a device current of the electron-emitting device is negative, and the predetermined time includes a time. Method of manufacturing electron source. 9. A method of manufacturing an electron source, comprising: a plurality of row wirings and column wirings provided on a substrate; and a plurality of electron-emitting devices connected to these wirings, respectively. Manufacture of an electron source having an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion by applying a voltage to the electron emitting element in an atmosphere of an activated gas after forming the emitting portion. In the method, in the activation step, a voltage is uniformly applied to all the electron-emitting devices connected to one wiring for each row wiring or column wiring,
An operation of applying a compensating voltage for compensating for the voltage drop caused by one wire to each electron-emitting device is performed, and in the course of this operation, the set value of the partial pressure of the activation gas is switched in multiple stages, and The method of manufacturing an electron source, wherein the compensation voltage is not applied for a predetermined time after the set value is switched. 10. A method of manufacturing an electron source, comprising: a plurality of row wirings and column wirings provided on a substrate; and a plurality of electron-emitting devices connected to these wirings, respectively. Manufacture of an electron source having an activation step of depositing carbon or a carbon compound in a region including the electron emitting portion by applying a voltage to the electron emitting element in an atmosphere of an activated gas after forming the emitting portion. In the method, in the activation step, a voltage is uniformly applied to all the electron-emitting devices connected to one wiring for each row wiring or column wiring,
An operation of applying a compensation voltage for compensating for a voltage drop caused by one wire to each electron-emitting device is performed, and this operation is repeated a plurality of times while switching the one row wire or the column wire, and A method of manufacturing an electron source, wherein the compensation voltage is not applied for a predetermined time after the switching of one row wiring or column wiring. 11. The compensation voltage according to claim 1, wherein a value of a current flowing through one wire is measured and a calculation is performed based on a result of the measurement. Method of manufacturing electron source.